Negative-pressure-type booster

Abstract

A negative-pressure-type booster includes: a booster shell attached to a support member of a vehicle; a front shell and a rear shell which constitute the booster shell; and, at the four corners of a flat part of the rear shell, linking bolts having affixed thereto protruding parts that each protrude rearward from the flat part, the protruding parts being passed through continuous connecting holes in the support member, the negative-pressure-type booster characterized in that the linking bolts are composed of upper linking bolts arranged to the upper side of the center axis of the booster shell and lower linking bolts arranged to the lower side of the center axis of the booster shell, the protruding part of either of the upper linking bolts extending farther rearward than the protruding part of the other upper linking bolt and the respective protruding parts of the lower linking bolts.

The invention claimed is: 
     
       1. A negative-pressure-type booster comprising:
 a booster shell attached to a support member of a vehicle; 
 a front shell and a rear shell configuring the booster shell; and 
 at four corners of a flat part of the rear shell, linking bolts to which protruding parts protruding rearward from the flat part are fixed, the protruding parts being inserted into connecting holes of the support member, wherein 
 the linking bolts include upper linking bolts disposed on an upper side of a center axis of the booster shell and lower linking bolts disposed on a lower side of the center axis of the booster shell, 
 the protruding part of any one of the upper linking bolts extends more rearward than the protruding part of the other upper linking bolt and the protruding parts of the lower linking bolts. 
 
     
     
       2. The negative-pressure-type booster according to  claim 1 , wherein the lower linking bolt located on a diagonal line of the one of the upper linking bolts is formed such that the lower linking bolt has a length equal to that of the one of the upper linking bolts. 
     
     
       3. The negative-pressure-type booster according to  claim 1 , wherein, in the one of the upper linking bolts, a cutout caught by the support member of the vehicle when the upper linking bolt is inserted into the support member is formed. 
     
     
       4. The negative-pressure-type booster according to  claim 2 , wherein, in the one of the upper linking bolts, a cutout caught by the support member of the vehicle when the upper linking bolt is inserted into the support member is formed. 
     
     
       5. A negative-pressure-type booster comprising:
 a front shell and a rear shell constituting a booster shell; 
 the booster shell being attached to a support member of a vehicle; and 
 at four corners of a flat part of the rear shell, linking bolts to which protruding parts protruding rearward from the flat part are fixed, the protruding parts being inserted into connecting holes of the support member, wherein 
 the linking bolts include upper linking bolts disposed on an upper side of a center axis of the booster shell and lower linking bolts disposed on a lower side of the center axis of the booster shell, 
 the protruding part of any one of the upper linking bolts extends more rearward than the protruding part of the other upper linking bolt and also extends more rearward than the protruding part of at least one of the lower linking bolts. 
 
     
     
       6. The negative-pressure-type booster according to  claim 5 , wherein the lower linking bolt located on a diagonal line of the one of the upper linking bolts has a length equal to that of the one of the upper linking bolts. 
     
     
       7. The negative-pressure-type booster according to  claim 6 , wherein the one of the upper linking bolts includes a cutout caught by the support member of the vehicle when the upper linking bolt is inserted into the support member. 
     
     
       8. The negative-pressure-type booster according to  claim 5 , wherein the one of the upper linking bolts includes a cutout caught by the support member of the vehicle when the upper linking bolt is inserted into the support member.